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III IIIIIIIIIIIIIIII • <br />999 <br />• <br />STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />DeVartmenl of Natural Resources <br />1313 Sherman St., Room 215 <br />Denver, Colorado 80203 <br />Phone: 1303) 866-3567 <br />FAX: 13031 872-8106 <br />April 3, 1997 <br />To: Kent Gorham <br />DEPARTMENT OF <br />NATURAL <br />RESOURCES <br />Roy Romer <br />From: Janet Binns cOVef°°` <br />lames 5. Lochhead <br />Executive Director <br />Michael B. Long <br />Re: C-81-012, Eagle Mine, Technical Revision No. 43 Division Director <br />I have reviewed Basin Resources TR-43 for a topsoil borrow azea. I did not review the portions <br />pertaining to a change in post-mining topography. Any changes in topography resulting from <br />taking the borrow area material will be an insignificant change and therefore not an issue. <br />Overall, the topsoil resource Basin proposes to utilize as borrow material is suitable to use on the <br />Refuse Disposal Area (RDA). The subsoil, B horizon, that would remain at the borrow area, <br />does not appear limiting based upon the soil description and the sample analysis. Basin proposes <br />to rip, seed, and mulch the borrow area when reclaiming. Ripping should relieve compaction <br />that may occur during soil salvage operations. Basin does not define how deep this subsoil will <br />be ripped. Mulch application rate is defined on permit page 2.05-25c as two tons per acre, <br />crimped into the soil. This should help provide some organic matter into the soil in addition to <br />providing erosion protection. <br />1) Basin needs to define how deep the subsoil will be ripped during seedbed preparation. <br />The soil proposed to be utilized in [he borrow area is mapped as Noden loam. Soil sampling <br />analysis agrees with this mapping designation. The corresponding NRCS Range Site Description <br />is the Loamy Foothills. Additional information regarding this soil type description may be found <br />in Exhibit 12 of the Golden Eagle Permit. Phosphorus appears lacking in all four of the samples <br />collected from the borrow area. The Noden Soil description by the NRCS confirms that <br />vegetation on this soil type responds favorably to Phosphorus and Nitrogen additions. Studies <br />conducted aL the Allen Mine in 1979-1981, Exhibit 20, further affirms that fertilizer addition is <br />warranted. <br />2) Based upon Colorado State University Extension Service Technical Note XCM-37, <br />"Guide to Fertilizer Recommendations in Colorado", and Basin Resources Fertility <br />Analysis of the Topsoil Borrow material, the Division recommends application of <br />801bs/acre of P205 to be applied to the root zone at seeding. Permit Exhibit 20 <br />recommends application of 66 kg N/ha on these soils. <br />~ ~ a 2. X71 ~,~ ~ -~c~ <br />,~K351 K~ <br />